| Popis: |
The aim of my bachelor thesis was to evaluate the effect of fish oil substitution for rapeseed oil in the feed on the fat content and fatty acid composition in the flesh of Brook trout (Salvelinus fontinalis) in the finishing feeding technology. The experiment was conducted in 2012 for the period of 135 days. The individuals of Brook trout were divided into four groups. The first two groups were fed with the feed containing only rapeseed or fish oil. The feeding of the remaining two groups was divided into two phases. In the first phase the fish oil was partly replaced by the rapeseed oil. In the second phase the fish oil was replaced by the feed which contained fish oil only. It was proved that a half replacement of the fish oil with the rapeseed oil does not influence the content of fat in the flesh of Brook trout. We observed that the fish had the higher content of MUFA and n-6 PUFA and lower content of n-3 PUFA, DHA, EPA and n-3/n-6 with increasing period where the feed with rapeseed oil was served. Following application of the finishing feeding technology with the use of feed with fish oil had the opposite effects. Furthermore, the dilution model was proved to be highly reliable for the prediction of the fatty acids composition. Based on these findings, it is possible to predict changes of fatty acid composition in the flesh of Brook trout as well as to predict how long is needed to apply finishing feeding to reach required content of EPA+DHA or n-3 HUFA. |
